Layered product ready for non touch application and a method for producing such a product

ABSTRACT

A layered product in a package ready for non-touch application which product comprises a cover layer to which an adhesive layer is unreleasably fastened and a release layer which is releasably fastened to the adhesive layer, and which package comprises a top layer and a bottom layer where the top layer is next to the cover layer and the bottom layer is next to the adhesive layer or the release layer and the top and bottom layer are releasably sealed to each other isolating the adhesive layer from the surroundings, and where the cover layer is releasably fastened to the top layer.

FIELD OF THE INVENTION

The present invention relates to a layered product in a package readyfor non-touch application which product comprises a cover layer to whichan adhesive layer is unreleasably fastened and a release layer which isreleasably fastened to the adhesive layer. The package comprises a toplayer and a bottom layer where the top layer is next to the cover layerand the bottom layer is next to the adhesive layer and the top andbottom layers are releasably sealed to each other isolating the adhesivelayer from the surroundings.

BACKGROUND OF THE INVENTION

It is desirable to be able to apply an adhesive product such as adressing without touching the adhesive layer in order to avoid reducingthe adhesiveness of the product. Also it is desirable to be able toapply a sterile dressing to a patient's skin without touching thesurface of the dressing that is to come into contact with the skin inorder to avoid introducing bacteria to the wound.

The prior art discloses several methods for facilitating handling ofwound dressings and one method is described in U.S. Pat. No. 5,106,629(NDM Acquisition Corp.). The product of this patent is constituted ofthree layers: a dimensionally stable backing layer, a transparentadhesive layer and a release layer. When applying the dressing, therelease layer is removed by using an extending tab attached thereto, toexpose the adhesive layer. The remaining layers of the wound dressingare then applied to the wound site with the adhesive layer directlycontacting the wound. Once these layers are in place, the dimensionallystable backing member is removed, preferably using an extending tabattached hereto.

Another method is described in WO 97/43991 (Coloplast A/S). The objectof this invention is to ensure easy handling of a wound dressing whichcomprises a main part and a handle part. The main part comprises acarrier layer, an adhesive layer and a release liner. The handle partcomprises one or more tab members designed for use as a “non-touch” gripwhen applying the dressing to the skin. The tab member and the main partof the dressing do not have all layers in common, reducing the forcewhich needs to be applied in order to remove the tab member afterapplying the dressing.

These two documents explain how to handle the product without touchingthe adhesive during application but they do not combine discretepackaging of the products with non-touch application of the products.

A third product—a medical adhesive composite—is described in WO 98/00080(Minnesota Mining and Manufacturing Company). This medical adhesivecomposite, e.g. a dressing, is combined with a package, the packagedproduct comprises a top sheet of packaging material, a carrier material,a conformable backing material, a pressure sensitive adhesive and abottom sheet of packaging material with a release surface. The carriermaterial is preferably substantially more rigid than the backingmaterial in order to prevent the backing from wrinkling or folding ontoitself in whole or in part during application of the dressing. Thecarrier material is capable of being attached to the backing by anysuitable method, such as heat sealing, adhesives, mechanical bonds, waxcoatings etc. The bond is secure, yet releasable, i.e. the carrier andbacking can be separated without destroying the integrity of the backingor the bond between the adhesive on the backing and the skin of apatient. In addition the bond between the carrier and the backing shouldbe stronger than the bond between the adhesive on the bottom face of thebacking and the release liner or surface of the packaging. Adhering themedical adhesive composites directly to the bottom sheet of thepackaging material rather than including a separate release liner on theproduct simplifies the process of dispensing the medical adhesivecomposites. The bond strength between the release surface and the bottomsheet is greater than the bond strength between the release surface andthe adhesive on the bottom face of the backing.

This document shows how it is possible to include packaging of theproduct into a single process but the used process is rather complicatedand the packaged product may be difficult to apply.

In EP Patent Application No. 938 882 is disclosed a release paper in theform of a sheet with several discrete plasters. The plasters comprise anadhesive layer, covered on one side with the release paper and on theother side with a top film. A pouch covering the wound area maybelocated between the adhesive and the release paper. The plasters areseparated from each other by a perforated line in the release paper. Theproduct is not in the form of a sealed package as it does not comprise asealing cover layer on top of the construction.

BRIEF DESCRIPTION OF THE INVENTION

The object of the invention is to provide a product in a discretepackage which product is easy to handle without the user touching theadhesive of the product which will be touching the surface to which theproduct is applied, and at the same time this product is easier and lessexpensive to produce.

This object is achieved by fastening the cover layer releasably to thetop layer of the package in order to make it possible to use the toplayer as a non-touch grip.

A carrier layer is a coherent web which is used to move the layeredproduct through the production process even after other layers have beencut into their final size and it reduces the cost of production when thecarrier layer is made a part of the finished product instead of wastingthe carrier layer totally or partly during the production process.

In order to make the process very simple, the top layer may be thecarrier layer but it is also possible to use a second layer as carrierlayer and, in this case, the second layer may be present between thecover layer and the top layer in the finished product. In this case thebond strength R1 between the cover layer and the second layer is smallerthan the bond strength S1 between the second layer and the top layer. Infact S1 may be so large it is considered unreleasable.

It is possible to add a release layer as a separate layer and usestandard material for the process; otherwise the release layer can be arelease surface on the upper side of the bottom layer of the package.

In order to make the application procedure as simple as possible for theuser of the product it is advantageous that:

1) the bond strength R1 between the top layer of the package or a secondlayer and the cover layer is higher than the bond strength R2 betweenthe adhesive layer and the release layer, and

2) the bond strength R4 between the release layer and the bottom layerof the package is higher than the bond strength R2 between the adhesivelayer and the release layer, and

3) the bond strength between the adhesive layer and the surface to whichthe product has been applied is higher than the bond strength R1.

When the user applies a dressing which agrees with the above demands forthe bond strength between the different layers, the user first separatesthe top layer and the bottom layer of the package. When doing this, therelease layer—whether this layer is a part of the bottom layer or aseparate layer—will come off together with the bottom layer andafterwards the bottom layer and the release layer can be thrown away.This leaves the user with the top layer to which the product comprisingthe cover layer and an adhesive layer is attached. Now the user can usethe top layer of the package to handle the product and assure theproduct is placed correctly. When the adhesion between the layeredproduct and the surface to which the product is fastened is higher thanthe bond strength between the top layer and the cover layer, the usercan remove the top layer of the package from the applicated productwithout problems and throw it away.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional view of a product and a package accordingto the present invention.

FIG. 2 is a schematic diagram of a continuous method of manufacturing aproduct according to the present invention.

FIG. 3 is a schematic diagram of a batchwise method of manufacturing aproduct according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a cross-sectional view of a product and a package. Thepackage is constituted by two outer layers, namely a top layer 1 and abottom layer 2. These two layers are sealed together at 3 in a way thatcompletely isolates the product from the surroundings, and the sealingrepresents a bond strength of R3.

A cover layer 4 is placed below the top layer and these two layers arereleasably fastened to each other with the bond strength R1. Thefunction of the cover layer 4 is to establish a non-adhesive andcomfortable upper side of the product when the product is in use. Whenthe product is a dressing, the cover layer can be woven or non-woven,e.g., a polymeric material such as a polyurethane with a certainpermeativity for water. It is also possible to place a separate layersuch as a carrier layer 7 between the top layer and the cover layer andthen the bond strength S1 between the top layer and the optional carrierlayer 7 can suitably be considerably higher than the bond strength R1between the cover layer and the carrier layer.

Below the cover layer 4 is an adhesive layer 5. The cover layer 4 andthe adhesive layer 5 are unreleasably bonded to each other. By“unreleasably bonded” it is understood that it is not possible toseparate the two layers and keep them both intact and, according to thisdefinition of “unreleasably”, the two layers may consist of one layerwith different surface structure on the upper and lower sides. If theproduct is a dressing, the adhesive may contain hydrocolloids.

The adhesive layer 5 is protected by a release surface. In FIG. 1 therelease surface is constituted by a separate layer, a release layer 6,but the release surface may also be a part of the surface of the bottomlayer having releasing qualities. The bond strength between the adhesivelayer 5 and the release surface is R2. The bond strength between anoptional separate release layer 6 and the bottom layer 2 is R4.

FIG. 2 shows a schematic diagram of a continuous process which may beused for manufacturing the product of this invention. The primarylayered web 9 that enters the process comprises a carrier layer which inthis example is the later top layer 1 of the package, a cover layer 4which will form a non-adhesive surface of the applicated product and alayer of or discrete portions of adhesive 5 which has/have been fastenedunreleasably to the cover layer 4.

A roll 10 contains a supply of release liner and the release liner isattached to the primary layered web 9 at the roll 11. Hereafter theprimary web 9 to which the release liner now is attached passes astation 12 where the layers of the web which constitute the product,thecover layer 4, the adhesive layer 5 and the release layer 6, are cutinto desired discrete products. The weed 13 from this action is removedand only the carrier layer—the top layer 1 of the package—stillconstitutes a coherent layer.

When the weed 13 has been removed it is time to add the bottom layer ofthe package to the line of products. A supply roll of the bottom layeris kept at 14 and the bottom layer is attached to the line of productsat the station 15.

After the bottom layer of the package has been attached to the line ofproducts, the individual products have to be isolated. This is done atthe station 16 where the top and the bottom layers of the package arefastened releasably to each other by, e.g., peel welding.

It is also possible to apply a more batchwise process for manufacturingof the products. This is especially advantageous if the processproducing the web 9 is very fast and it is difficult for a singlepackaging machine to keep up.

After the products have passed the roll 12 of FIG. 2 where the line ofproducts have been die cut, the endless line of products is cut up intounits containing several discrete products 22 (in FIG. 3 the unitscontain four discrete products). The units are then collected and movedto a temporary storage or directly to one or more different packingmachines. In order to be able to pile the units for storage or transportthe units have to be provided with a release liner.

In FIG. 3 is a schematic diagram of a batchwise process where the unitsconsisting of discrete products 22 arrive at the packing machines inpiles 21. The top unit is moved forward and placed on the bottom layer23 of the package, to which layer the release-liner covered surface ofthe product is fastened with the bond strength R4 by, e.g., gluing orpeel welding.

In this process the bottom layer 23 and the top layer 24 of the packageare constituted by a single sheet of package material. After placing andfastening the unit on the bottom layer, the top layer is folded over theunit and fastened to the bottom layer by the bond strength R3 and to thecover layer of the products by the bond strength R1, e.g., in such a waythat the products are isolated as discrete products.

What is claimed is:
 1. A layered product in a package at ready fornon-touch application comprising: a cover layer having an upper surfaceand a lower surface to which an adhesive layer is unreleasably fastened;a release layer which is releasably fastened to the adhesive layer; anda top layer and a bottom layer where the top layer is next to the coverlayer and the bottom layer is next to the release layer, said top andbottom layers being releasably sealed to each other isolating theadhesive layer from the surroundings, said upper surface of said coverlayer being releasably fastened directly to the top layer.
 2. Thelayered product in a package ready for non-touch application accordingto claim 1 wherein a carrier layer forms a part of the packaged product.3. The layered product in a package ready for non-touch applicationaccording to claim 2 wherein the top layer is also the carrier layer. 4.The layered product in a package ready for non-touch applicationaccording to claim 1 wherein: 1) a bond strength R1 between the toplayer of the package and the cover layer is higher than a bond strengthR2 between the adhesive layer and the release layer; 2) a bond strengthR4 between the release layer and the bottom layer of the package ishigher than the bond strength R2 between the adhesive layer and therelease layer; and 3) a bond strength between the adhesive layer and thesurface to which the product has been applied is higher than the bondstrength R1.
 5. A method for producing a layered product in a packagehaving a top layer and a bottom layer ready for non-touch applicationcomprising the steps of: a) providing a web having at least three layersincluding a carrier layer connected to or constituting the top layer ofa package, a cover layer and an adhesive layer, said cover layer andsaid adhesive layer being unreleasably fastened to each other; b) diecutting the product into discrete portions still attached to the carrierlayer; c) attaching the bottom layer to the adhesive side of theproduct; and d) isolating the product by sealing the top layer to thebottom layer in a way that completely isolates the product from thesurroundings.
 6. A method for producing a layered product in a packagehaving a top layer and a bottom layer ready for non-touch applicationcomprising the steps of: a) providing a web having at least three layersincluding a carrier layer connected to or constituting the top layer ofa package, a cover layer and an adhesive layer, said cover layer andsaid adhesive layer being unreleasably fastened to each other; b)attaching a release layer to said adhesive layer; c) die cutting theproduct into discrete portions still attached to the carrier layer; d)attaching the bottom layer to said adhesive layer; and e) sealing thetop layer to the bottom layer in a way that completely isolates theproduct from the surroundings.
 7. A method for applicating a layeredproduct packed in a package and prepared for non-touch applicationcomprising the steps of: 1) providing a top layer and a bottom layer ofthe package that are bonded to each other by a bond strength R3, with acover layer of the layered product being fastened to the top layer by abond strength R1 and an adhesive layer of said layered product beingfastened to a release layer by a bond strength R2, the bond strength R1being greater than R2 so the layered product will stay fastened to thetop layer; 2) separating the top and the bottom layers; 3) removing thebottom layer and the release layer; 4) adhering the layered product onthe surface to which the product needs to be applied, a bond strengthbetween said surface and the layered product being higher than the bondstrength R1; and 5) removing the top layer.
 8. A layered product in apackage ready for non-touch application comprising: a cover layer havingan upper surface and a lower surface to which an adhesive layer isunreleasably fastened; a release surface which is releasably fastened tothe adhesive layer; a top layer and a bottom layer releasably sealed toeach other to enclose and isolate the cover layer and adhesive layerfrom the surroundings, said bottom layer being next to the adhesivelayer; and a carrier layer between the top layer and the upper surfaceof the cover layer, said carrier layer being fastened to said top layerand releasably fastened to said upper surface of said cover layer. 9.The layered product in a package ready for non-touch applicationaccording to claim 8 wherein the release surface is integral with saidbottom layer.
 10. The layered product in a package ready for non-touchapplication according to claim 8 wherein a separate release layer ispresent between the adhesive layer and the bottom layer, said releaselayer having said release surface thereon.
 11. The layered product in apackage ready for non-touch application according to claim 10wherein: 1) a bond strength R1 between the carrier layer and the coverlayer is higher than a bond strength R2 between the adhesive layer andthe release layer; 2) a bond strength R4 between the release layer andthe bottom layer of the package is higher than the bond strength R2between the adhesive layer and the release layer; and 3) a bond strengthbetween the adhesive layer and the surface to which the product has beenapplied is higher than the bond strength R1.
 12. The layered product ina package ready for non-touch application according to claim 8 wherein abond strength R1 between the carrier layer and said cover layer issmaller than a bond strength S1 between said carrier layer and said toplayer.
 13. A layered product in a package ready for non-touchapplication comprising: a cover layer to which an adhesive layer isunreleasably fastened; a release layer which is releasably fastened tothe adhesive layer with a bond strength R2; a top layer and a bottomlayer releasably sealed to each other so as to enclose and isolate thecover layer and the adhesive layer from the surroundings, the bottomlayer being next to the release layer, and the top layer beingreleasably fastened to the cover layer with a bond strength R1 that isgreater than the bond strength R2.
 14. The layered product in a packageready for non-touch application according to claim 13 further comprisinga carrier layer present between and fastened to said cover layer andsaid top layer.
 15. The layered product in a package ready for non-touchapplication according to claim 14 wherein said cover layer is fastenedto said carrier layer with the bond strength R1 and said top layer isfastened to said carrier layer with a bond strength S1 that is largerthan the bond strength R1.